1 /* BFD support for the ns32k architecture.
2 Copyright 1990, 1991, 1994, 1995, 1998, 1999, 2000, 2001, 2002, 2003,
3 2004, 2005, 2007 Free Software Foundation, Inc.
4 Almost totally rewritten by Ian Dall from initial work
7 This file is part of BFD, the Binary File Descriptor library.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
22 MA 02110-1301, USA. */
29 #define N(machine, printable, d, next) \
30 { 32, 32, 8, bfd_arch_ns32k, machine, "ns32k",printable,3,d,bfd_default_compatible,bfd_default_scan, next, }
32 static const bfd_arch_info_type arch_info_struct[] =
34 N(32532,"ns32k:32532",TRUE, 0), /* The word ns32k will match this too. */
37 const bfd_arch_info_type bfd_ns32k_arch =
38 N(32032,"ns32k:32032",FALSE, &arch_info_struct[0]);
40 static bfd_reloc_status_type do_ns32k_reloc
41 PARAMS ((bfd *, arelent *, struct bfd_symbol *, PTR, asection *,
43 bfd_vma (*) (bfd_byte *, int),
44 void (*) (bfd_vma, bfd_byte *, int)));
47 _bfd_ns32k_get_displacement (buffer, size)
56 value = ((*buffer & 0x7f) ^ 0x40) - 0x40;
60 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
61 value = (value << 8) | (0xff & *buffer);
65 value = ((*buffer++ & 0x3f) ^ 0x20) - 0x20;
66 value = (value << 8) | (0xff & *buffer++);
67 value = (value << 8) | (0xff & *buffer++);
68 value = (value << 8) | (0xff & *buffer);
80 _bfd_ns32k_put_displacement (value, buffer, size)
95 *buffer++ = (value >> 8);
100 value |= (bfd_vma) 0xc0000000;
101 *buffer++ = (value >> 24);
102 *buffer++ = (value >> 16);
103 *buffer++ = (value >> 8);
111 _bfd_ns32k_get_immediate (buffer, size)
120 value = (value << 8) | (*buffer++ & 0xff);
121 value = (value << 8) | (*buffer++ & 0xff);
123 value = (value << 8) | (*buffer++ & 0xff);
125 value = (value << 8) | (*buffer++ & 0xff);
134 _bfd_ns32k_put_immediate (value, buffer, size)
143 *buffer-- = (value & 0xff); value >>= 8;
144 *buffer-- = (value & 0xff); value >>= 8;
146 *buffer-- = (value & 0xff); value >>= 8;
148 *buffer-- = (value & 0xff); value >>= 8;
152 /* This is just like the standard perform_relocation except we
153 use get_data and put_data which know about the ns32k storage
154 methods. This is probably a lot more complicated than it
157 static bfd_reloc_status_type
158 do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section, output_bfd,
159 error_message, get_data, put_data)
161 arelent *reloc_entry;
162 struct bfd_symbol *symbol;
164 asection *input_section;
166 char **error_message ATTRIBUTE_UNUSED;
167 bfd_vma (*get_data) PARAMS ((bfd_byte *, int));
168 void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));
172 bfd_reloc_status_type flag = bfd_reloc_ok;
173 bfd_size_type addr = reloc_entry->address;
174 bfd_vma output_base = 0;
175 reloc_howto_type *howto = reloc_entry->howto;
176 asection *reloc_target_output_section;
179 if ((symbol->section == &bfd_abs_section)
180 && output_bfd != (bfd *) NULL)
182 reloc_entry->address += input_section->output_offset;
186 /* If we are not producing relocatable output, return an error if
187 the symbol is not defined. An undefined weak symbol is
188 considered to have a value of zero (SVR4 ABI, p. 4-27). */
189 if (symbol->section == &bfd_und_section
190 && (symbol->flags & BSF_WEAK) == 0
191 && output_bfd == (bfd *) NULL)
192 flag = bfd_reloc_undefined;
194 /* Is the address of the relocation really within the section? */
195 if (reloc_entry->address > bfd_get_section_limit (abfd, input_section))
196 return bfd_reloc_outofrange;
198 /* Work out which section the relocation is targeted at and the
199 initial relocation command value. */
201 /* Get symbol value. (Common symbols are special.) */
202 if (bfd_is_com_section (symbol->section))
205 relocation = symbol->value;
207 reloc_target_output_section = symbol->section->output_section;
209 /* Convert input-section-relative symbol value to absolute. */
210 if (output_bfd != NULL && ! howto->partial_inplace)
213 output_base = reloc_target_output_section->vma;
215 relocation += output_base + symbol->section->output_offset;
217 /* Add in supplied addend. */
218 relocation += reloc_entry->addend;
220 /* Here the variable relocation holds the final address of the
221 symbol we are relocating against, plus any addend. */
223 if (howto->pc_relative)
225 /* This is a PC relative relocation. We want to set RELOCATION
226 to the distance between the address of the symbol and the
227 location. RELOCATION is already the address of the symbol.
229 We start by subtracting the address of the section containing
232 If pcrel_offset is set, we must further subtract the position
233 of the location within the section. Some targets arrange for
234 the addend to be the negative of the position of the location
235 within the section; for example, i386-aout does this. For
236 i386-aout, pcrel_offset is FALSE. Some other targets do not
237 include the position of the location; for example, m88kbcs,
238 or ELF. For those targets, pcrel_offset is TRUE.
240 If we are producing relocatable output, then we must ensure
241 that this reloc will be correctly computed when the final
242 relocation is done. If pcrel_offset is FALSE we want to wind
243 up with the negative of the location within the section,
244 which means we must adjust the existing addend by the change
245 in the location within the section. If pcrel_offset is TRUE
246 we do not want to adjust the existing addend at all.
248 FIXME: This seems logical to me, but for the case of
249 producing relocatable output it is not what the code
250 actually does. I don't want to change it, because it seems
251 far too likely that something will break. */
253 input_section->output_section->vma + input_section->output_offset;
255 if (howto->pcrel_offset)
256 relocation -= reloc_entry->address;
259 if (output_bfd != (bfd *) NULL)
261 if (! howto->partial_inplace)
263 /* This is a partial relocation, and we want to apply the relocation
264 to the reloc entry rather than the raw data. Modify the reloc
265 inplace to reflect what we now know. */
266 reloc_entry->addend = relocation;
267 reloc_entry->address += input_section->output_offset;
272 /* This is a partial relocation, but inplace, so modify the
275 If we've relocated with a symbol with a section, change
276 into a ref to the section belonging to the symbol. */
278 reloc_entry->address += input_section->output_offset;
281 if (abfd->xvec->flavour == bfd_target_coff_flavour)
283 /* For m68k-coff, the addend was being subtracted twice during
284 relocation with -r. Removing the line below this comment
285 fixes that problem; see PR 2953.
287 However, Ian wrote the following, regarding removing the line
288 below, which explains why it is still enabled: --djm
290 If you put a patch like that into BFD you need to check all
291 the COFF linkers. I am fairly certain that patch will break
292 coff-i386 (e.g., SCO); see coff_i386_reloc in coff-i386.c
293 where I worked around the problem in a different way. There
294 may very well be a reason that the code works as it does.
296 Hmmm. The first obvious point is that bfd_perform_relocation
297 should not have any tests that depend upon the flavour. It's
298 seem like entirely the wrong place for such a thing. The
299 second obvious point is that the current code ignores the
300 reloc addend when producing relocatable output for COFF.
301 That's peculiar. In fact, I really have no idea what the
302 point of the line you want to remove is.
304 A typical COFF reloc subtracts the old value of the symbol
305 and adds in the new value to the location in the object file
306 (if it's a pc relative reloc it adds the difference between
307 the symbol value and the location). When relocating we need
308 to preserve that property.
310 BFD handles this by setting the addend to the negative of the
311 old value of the symbol. Unfortunately it handles common
312 symbols in a non-standard way (it doesn't subtract the old
313 value) but that's a different story (we can't change it
314 without losing backward compatibility with old object files)
315 (coff-i386 does subtract the old value, to be compatible with
316 existing coff-i386 targets, like SCO).
318 So everything works fine when not producing relocatable
319 output. When we are producing relocatable output, logically
320 we should do exactly what we do when not producing
321 relocatable output. Therefore, your patch is correct. In
322 fact, it should probably always just set reloc_entry->addend
323 to 0 for all cases, since it is, in fact, going to add the
324 value into the object file. This won't hurt the COFF code,
325 which doesn't use the addend; I'm not sure what it will do
326 to other formats (the thing to check for would be whether
327 any formats both use the addend and set partial_inplace).
329 When I wanted to make coff-i386 produce relocatable output,
330 I ran into the problem that you are running into: I wanted
331 to remove that line. Rather than risk it, I made the
332 coff-i386 relocs use a special function; it's coff_i386_reloc
333 in coff-i386.c. The function specifically adds the addend
334 field into the object file, knowing that bfd_perform_relocation
335 is not going to. If you remove that line, then coff-i386.c
336 will wind up adding the addend field in twice. It's trivial
337 to fix; it just needs to be done.
339 The problem with removing the line is just that it may break
340 some working code. With BFD it's hard to be sure of anything.
341 The right way to deal with this is simply to build and test at
342 least all the supported COFF targets. It should be
343 straightforward if time and disk space consuming. For each
346 2) generate some executable, and link it using -r (I would
347 probably use paranoia.o and link against newlib/libc.a,
348 which for all the supported targets would be available in
349 /usr/cygnus/progressive/H-host/target/lib/libc.a).
350 3) make the change to reloc.c
351 4) rebuild the linker
353 6) if the resulting object files are the same, you have at
354 least made it no worse
355 7) if they are different you have to figure out which
357 relocation -= reloc_entry->addend;
358 reloc_entry->addend = 0;
362 reloc_entry->addend = relocation;
368 reloc_entry->addend = 0;
371 /* FIXME: This overflow checking is incomplete, because the value
372 might have overflowed before we get here. For a correct check we
373 need to compute the value in a size larger than bitsize, but we
374 can't reasonably do that for a reloc the same size as a host
376 FIXME: We should also do overflow checking on the result after
377 adding in the value contained in the object file. */
378 if (howto->complain_on_overflow != complain_overflow_dont)
382 /* Get the value that will be used for the relocation, but
383 starting at bit position zero. */
384 if (howto->rightshift > howto->bitpos)
385 check = relocation >> (howto->rightshift - howto->bitpos);
387 check = relocation << (howto->bitpos - howto->rightshift);
388 switch (howto->complain_on_overflow)
390 case complain_overflow_signed:
392 /* Assumes two's complement. */
393 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
394 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
396 /* The above right shift is incorrect for a signed value.
397 Fix it up by forcing on the upper bits. */
398 if (howto->rightshift > howto->bitpos
399 && (bfd_signed_vma) relocation < 0)
400 check |= ((bfd_vma) - 1
402 >> (howto->rightshift - howto->bitpos)));
403 if ((bfd_signed_vma) check > reloc_signed_max
404 || (bfd_signed_vma) check < reloc_signed_min)
405 flag = bfd_reloc_overflow;
408 case complain_overflow_unsigned:
410 /* Assumes two's complement. This expression avoids
411 overflow if howto->bitsize is the number of bits in
413 bfd_vma reloc_unsigned_max =
414 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
416 if ((bfd_vma) check > reloc_unsigned_max)
417 flag = bfd_reloc_overflow;
420 case complain_overflow_bitfield:
422 /* Assumes two's complement. This expression avoids
423 overflow if howto->bitsize is the number of bits in
425 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
427 if (((bfd_vma) check & ~reloc_bits) != 0
428 && (((bfd_vma) check & ~reloc_bits)
429 != (-(bfd_vma) 1 & ~reloc_bits)))
431 /* The above right shift is incorrect for a signed
432 value. See if turning on the upper bits fixes the
434 if (howto->rightshift > howto->bitpos
435 && (bfd_signed_vma) relocation < 0)
437 check |= ((bfd_vma) - 1
439 >> (howto->rightshift - howto->bitpos)));
440 if (((bfd_vma) check & ~reloc_bits)
441 != (-(bfd_vma) 1 & ~reloc_bits))
442 flag = bfd_reloc_overflow;
445 flag = bfd_reloc_overflow;
454 /* Either we are relocating all the way, or we don't want to apply
455 the relocation to the reloc entry (probably because there isn't
456 any room in the output format to describe addends to relocs). */
458 /* The cast to bfd_vma avoids a bug in the Alpha OSF/1 C compiler
459 (OSF version 1.3, compiler version 3.11). It miscompiles the
473 x <<= (unsigned long) s.i0;
477 printf ("succeeded (%lx)\n", x);
481 relocation >>= (bfd_vma) howto->rightshift;
483 /* Shift everything up to where it's going to be used. */
484 relocation <<= (bfd_vma) howto->bitpos;
486 /* Wait for the day when all have the mask in them. */
489 i instruction to be left alone
490 o offset within instruction
491 r relocation offset to apply
500 i i i i i o o o o o from bfd_get<size>
501 and S S S S S to get the size offset we want
502 + r r r r r r r r r r to get the final value to place
503 and D D D D D to chop to right size
504 -----------------------
507 ... i i i i i o o o o o from bfd_get<size>
508 and N N N N N get instruction
509 -----------------------
515 -----------------------
516 R R R R R R R R R R put into bfd_put<size>. */
519 x = ( (x & ~howto->dst_mask) | (((x & howto->src_mask) + relocation) & howto->dst_mask))
521 location = (bfd_byte *) data + addr;
526 bfd_vma x = get_data (location, 1);
528 put_data ((bfd_vma) x, location, 1);
535 bfd_vma x = get_data (location, 2);
537 put_data ((bfd_vma) x, location, 2);
543 bfd_vma x = get_data (location, 4);
545 put_data ((bfd_vma) x, location, 4);
550 bfd_vma x = get_data (location, 4);
551 relocation = -relocation;
553 put_data ((bfd_vma) x, location, 4);
565 bfd_vma x = get_data (location, 8);
567 put_data (x, location, 8);
574 return bfd_reloc_other;
576 if ((howto->complain_on_overflow != complain_overflow_dont) && overflow)
577 return bfd_reloc_overflow;
582 /* Relocate a given location using a given value and howto. */
584 bfd_reloc_status_type
585 _bfd_do_ns32k_reloc_contents (howto, input_bfd, relocation, location,
587 reloc_howto_type *howto;
588 bfd *input_bfd ATTRIBUTE_UNUSED;
591 bfd_vma (*get_data) PARAMS ((bfd_byte *, int));
592 void (*put_data) PARAMS ((bfd_vma, bfd_byte *, int));
596 bfd_boolean overflow;
598 /* If the size is negative, negate RELOCATION. This isn't very
601 relocation = -relocation;
603 /* Get the value we are going to relocate. */
604 size = bfd_get_reloc_size (howto);
616 x = get_data (location, size);
620 /* Check for overflow. FIXME: We may drop bits during the addition
621 which we don't check for. We must either check at every single
622 operation, which would be tedious, or we must do the computations
623 in a type larger than bfd_vma, which would be inefficient. */
625 if (howto->complain_on_overflow != complain_overflow_dont)
628 bfd_signed_vma signed_check;
630 bfd_signed_vma signed_add;
632 if (howto->rightshift == 0)
635 signed_check = (bfd_signed_vma) relocation;
639 /* Drop unwanted bits from the value we are relocating to. */
640 check = relocation >> howto->rightshift;
642 /* If this is a signed value, the rightshift just dropped
643 leading 1 bits (assuming twos complement). */
644 if ((bfd_signed_vma) relocation >= 0)
645 signed_check = check;
647 signed_check = (check
649 & ~((bfd_vma) - 1 >> howto->rightshift)));
652 /* Get the value from the object file. */
653 add = x & howto->src_mask;
655 /* Get the value from the object file with an appropriate sign.
656 The expression involving howto->src_mask isolates the upper
657 bit of src_mask. If that bit is set in the value we are
658 adding, it is negative, and we subtract out that number times
659 two. If src_mask includes the highest possible bit, then we
660 can not get the upper bit, but that does not matter since
661 signed_add needs no adjustment to become negative in that
664 if ((add & (((~howto->src_mask) >> 1) & howto->src_mask)) != 0)
665 signed_add -= (((~howto->src_mask) >> 1) & howto->src_mask) << 1;
667 /* Add the value from the object file, shifted so that it is a
669 if (howto->bitpos == 0)
672 signed_check += signed_add;
676 check += add >> howto->bitpos;
678 /* For the signed case we use ADD, rather than SIGNED_ADD,
679 to avoid warnings from SVR4 cc. This is OK since we
680 explicitly handle the sign bits. */
682 signed_check += add >> howto->bitpos;
684 signed_check += ((add >> howto->bitpos)
686 & ~((bfd_vma) - 1 >> howto->bitpos)));
689 switch (howto->complain_on_overflow)
691 case complain_overflow_signed:
693 /* Assumes two's complement. */
694 bfd_signed_vma reloc_signed_max = (1 << (howto->bitsize - 1)) - 1;
695 bfd_signed_vma reloc_signed_min = ~reloc_signed_max;
697 if (signed_check > reloc_signed_max
698 || signed_check < reloc_signed_min)
702 case complain_overflow_unsigned:
704 /* Assumes two's complement. This expression avoids
705 overflow if howto->bitsize is the number of bits in
707 bfd_vma reloc_unsigned_max =
708 (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
710 if (check > reloc_unsigned_max)
714 case complain_overflow_bitfield:
716 /* Assumes two's complement. This expression avoids
717 overflow if howto->bitsize is the number of bits in
719 bfd_vma reloc_bits = (((1 << (howto->bitsize - 1)) - 1) << 1) | 1;
721 if ((check & ~reloc_bits) != 0
722 && (((bfd_vma) signed_check & ~reloc_bits)
723 != (-(bfd_vma) 1 & ~reloc_bits)))
732 /* Put RELOCATION in the right bits. */
733 relocation >>= (bfd_vma) howto->rightshift;
734 relocation <<= (bfd_vma) howto->bitpos;
736 /* Add RELOCATION to the right bits of X. */
737 x = ((x & ~howto->dst_mask)
738 | (((x & howto->src_mask) + relocation) & howto->dst_mask));
740 /* Put the relocated value back in the object file. */
752 put_data (x, location, size);
756 return overflow ? bfd_reloc_overflow : bfd_reloc_ok;
759 bfd_reloc_status_type
760 _bfd_ns32k_reloc_disp (abfd, reloc_entry, symbol, data, input_section,
761 output_bfd, error_message)
763 arelent *reloc_entry;
764 struct bfd_symbol *symbol;
766 asection *input_section;
768 char **error_message;
770 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
771 output_bfd, error_message,
772 _bfd_ns32k_get_displacement,
773 _bfd_ns32k_put_displacement);
776 bfd_reloc_status_type
777 _bfd_ns32k_reloc_imm (abfd, reloc_entry, symbol, data, input_section,
778 output_bfd, error_message)
780 arelent *reloc_entry;
781 struct bfd_symbol *symbol;
783 asection *input_section;
785 char **error_message;
787 return do_ns32k_reloc (abfd, reloc_entry, symbol, data, input_section,
788 output_bfd, error_message, _bfd_ns32k_get_immediate,
789 _bfd_ns32k_put_immediate);
792 bfd_reloc_status_type
793 _bfd_ns32k_final_link_relocate (howto, input_bfd, input_section, contents,
794 address, value, addend)
795 reloc_howto_type *howto;
797 asection *input_section;
805 /* Sanity check the address. */
806 if (address > bfd_get_section_limit (input_bfd, input_section))
807 return bfd_reloc_outofrange;
809 /* This function assumes that we are dealing with a basic relocation
810 against a symbol. We want to compute the value of the symbol to
811 relocate to. This is just VALUE, the value of the symbol, plus
812 ADDEND, any addend associated with the reloc. */
813 relocation = value + addend;
815 /* If the relocation is PC relative, we want to set RELOCATION to
816 the distance between the symbol (currently in RELOCATION) and the
817 location we are relocating. Some targets (e.g., i386-aout)
818 arrange for the contents of the section to be the negative of the
819 offset of the location within the section; for such targets
820 pcrel_offset is FALSE. Other targets (e.g., m88kbcs or ELF)
821 simply leave the contents of the section as zero; for such
822 targets pcrel_offset is TRUE. If pcrel_offset is FALSE we do not
823 need to subtract out the offset of the location within the
824 section (which is just ADDRESS). */
825 if (howto->pc_relative)
827 relocation -= (input_section->output_section->vma
828 + input_section->output_offset);
829 if (howto->pcrel_offset)
830 relocation -= address;
833 return _bfd_ns32k_relocate_contents (howto, input_bfd, relocation,